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Derivatives. (Details) - USD ($) | 12 Months Ended
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Dec. 31, 2020 | Dec. 31, 2019
Derivative [Member] |  |
Derivatives. (Details) [Line Items] |  |
Recognized gains and losses due to change in fair value | $ 14,780,000 | $ 555,000

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- Definition Amount of gain (loss) from the increase (decrease) in fair value of derivative and nonderivative instruments designated as fair value hedging instruments recognized in the income statement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 25 -Section 50 -Paragraph 1 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=121577467&loc=d3e76258-113986 + Details
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